In the past, computing applications such as computer games and multimedia applications used controllers, remotes, keyboards, mice, or the like to allow users to manipulate game characters or other aspects of an application. More recently, computer games and multimedia applications have begun employing cameras and software gesture recognition engines to provide a natural user interface (“NUT”). With NUI, raw joint data and user gestures are detected, interpreted and used to control game characters or other aspects of an application.
One of the challenges of a NUI system is distinguishing a person in the field of view of an image sensor, and correctly identifying the positions of his or her body parts including hands and fingers within the field of view. Routines are known for tracking arms, legs, heads and torso. However, given the subtle detail and wide variety of positions of a user's hands, conventional systems are not able to satisfactorily recognize and track a user's body including finger and hand positions. Detecting whether a user's hand is open or closed can be used in a wide variety of control and/or application metrics. It would be useful to have a system capable of reliably detecting the open or closed state of the user's hand(s).